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Biomedical subjects

K Setälä

Publications and source records attributed to K Setälä.

At least 19 recordsLinked to original sources

Wernicke's encephalopathy: is diffusion-weighted MRI useful?

We present the clinical and magnetic resonance imaging (MRI) findings of five patients with acute Wernicke's encephalopathy. T2-weighted and fluid-attenuated inversion recovery (FLAIR) images demonstrated symmetrical hyperintense lesions within the dorsomedial thalami, periaqueductal white matter, and the tectum of the midbrain. None of the lesions enhanced with gadolinium. In addition to conventional MRI sequences, we performed diffusion-weighted imaging (DWI). In all patients, DWI showed symmetrical pathologic thalamic and midbrain signal hyperintensities more distinctly than did conventional T2-weighted or FLAIR sequences. The apparent diffusion coefficient (ADC) map images showed slight signal reductions in four patients, suggesting restricted diffusion within these regions. In one patient, the signal intensity within the affected thalami was isointense with the ipsilateral basal ganglia on ADC map images. For enhanced detection of pathology, we conclude that DWI should be included in the imaging protocols of patients suspected to suffer from Wernicke's encephalopathy.

Acute Disease↗

Corneal thickness and corneal endothelium in normotensive subjects with unilateral exfoliation syndrome.

PURPOSE: To examine the central corneal thickness (CCT) and corneal endothelium in both eyes of patients with unilateral exfoliation syndrome (EXS). To determine the effect of CCT on the measurement of intraocular pressure (IOP). METHODS: In this cross-sectional clinical study, comparisons were made of CCT (Humphrey Ultrasonic Pachometer), corneal endothelial cells (Keeler-Konan contact specular microscope) and IOP (Goldmann applanation tonometer) between the exfoliative (E) and fellow nonexfoliative (NE) eyes in 40 normotensive patients with unilateral EXS. The CCT was used to obtain a corrected value for the IOP. RESULTS: The E eyes had significantly higher values for CCT (0.528+/-0.030 vs 0.523+/-0.032 mm, P<0.01) and IOP (15.7+/-3.6 vs 14.4+/-2.9 mmHg, P<0.001) than the fellow NE eyes. The paired E and NE eyes did not differ in endothelial cell density (2779+/-540 vs 2870+/-386 cells/mm2), in the coefficient of variation of cell size (0.25+/-0.03 vs 0.26+/-0.03) or in the frequency of hexagonal cells (80.5+/-6.5 vs 82.0+/-5.0%). After correcting IOP for CCT, the E eyes still had significantly higher IOP than the NE eyes (15.1+/-4.4 vs 14.2+/-3.7 mmHg, P<0.05). CONCLUSION: Normotensive eyes with early EXS did not have quantitative (cell density) or qualitative (variation in cell size, frequency of hexagonal cells) morphological changes in corneal endothelium, but had higher values for IOP and CCT. After correcting IOP for CCT, the E eyes still had significantly higher IOP than the fellow NE eyes.

Aged↗

Ocular findings in 34 patients with Alport syndrome: correlation of the findings to mutations in COL4A5 gene.

PURPOSE: To describe the incidence and type of ocular findings of 34 patients with Alport syndrome and to analyze the association of gene defect in COL4A5 gene to ocular abnormalities found. METHODS: A nationwide search of Alport syndrome patients was performed in Finland, and patients were invited to take part in a thorough ophthalmologic investigation. RESULTS: A total of 34 Alport syndrome patients from 14 different pedigrees were examined, and ocular abnormalities were found in 32% of them. The visual acuities were normal except in 4 of the 34 patients. Six individuals had retinal flecks and 4 men had anterior lenticonus. In 57% of the pedigrees the defect in COL4A5 gene was known. CONCLUSION: Ocular abnormalities were rare in childhood and increased with age. There was no correlation between the type of mutation and the type of ocular changes. In addition, the penetrance of the ocular findings varied considerably within most families.

Adolescent↗

Follow-up study of human corneal endothelial cells, photographed in vivo before enucleation and 20 years later in grafts.

PURPOSE: To evaluate the long-term (20-year) survival of transplanted human corneal endothelial cells. METHODS: The donor endothelium had been photographed 20 years ago with a specular microscope both before enucleation in the melanomatous eye and in situ after keratoplasty. The same donor endothelial cells were now photographed again 20 years later with a modern specular microscope to ascertain the morphology and cell density of the grafts. RESULTS: In the earlier study the mean postoperative endothelial cell density was 1357+/-543 cells/mm2, the average cell loss 11 months postoperatively being 48.2%; 20.5 years postoperatively the cell loss was 62.9% of the preoperative cell count. In our well-documented patient population the endothelial cell loss during the last 19 years had been only 14.7%, which amounts to a cell loss of less than 1% per year. CONCLUSION: In transplanted corneas, the main endothelial cell loss seems to take place during the first 1-2 postoperative years.

Cell Count↗

Effects of experimental exposure to triethylamine on vision and the eye.

OBJECTIVES: To determine the effect of triethylamine (TEA) on the cornea and to evaluate the cause of blurred vision. To find the lowest observed effect concentration of exposure to TEA. METHODS: Four people were exposed to TEA for 4 hours at concentrations of 40.6, 6.5, and 3.0 mg/m3. Before and after every exposure, symptoms and ocular microscopy findings were recorded. Binocular visual acuity and contrast sensitivity at 2.5% contrast were also measured. Also, before and after the 40.6 mg/m3 exposure, corneal thickness was measured and ocular dimensions were recorded by ultrasonography, endothelial cells of the cornea were analysed, and serum and lacrimal specimens were collected for the analysis of TEA. RESULTS: After exposure to 40.6 mg/m3 TEA there was a marked oedema in the corneal epithelium and subepithelial microcysts. However, corneal thickness increased only minimally because of the epithelial oedema. The lacrimal concentrations of TEA were, on average (range) 41 (18-83) times higher than the serum TEA concentrations. The vision was blurred in all subjects and visual acuity and contrast sensitivity had decreased in three of the four subjects. After exposure to TEA at 6.5 mg/m3 two subjects experienced symptoms, and contrast sensitivity had decreased in three of the four subjects. There were no symptoms or decreases in contrast sensitivity after exposure to a TEA concentration of 3.0 mg/m3. CONCLUSIONS: TEA caused a marked oedema and microcysts in corneal epithelium but only minor increases in corneal thickness. The effects may be mediated by the lacrimal fluid owing to its high TEA concentration. Four hour exposure to a TEA concentration of 3.0 mg/m3 seemed to cause no effects, whereas exposure to 6.5 mg/m3 for the same period caused blurred vision and a decrease in contrast sensitivity.

Adult↗

Effects of long-term contact lens wear on the corneal endothelium.

PURPOSE: To analyze the long-term effects of soft and hard (PMMA) contact lenses (CL) on the human corneal endothelium. METHODS: One hundred and one contact lens wearers with > or =10 years' wearing time and 50 healthy control subjects were examined with specular microscope. RESULTS: The mean corneal endothelial cell densities of the CL wearers (2846 cells/mm2) and of the control eyes (2940 cells/mm2) differed by 94 cells/mm2 (p<0.05). The mean values for the coefficient of variation (CV) differed significantly (p<0.0001); for all CL wearers: mean CV=0.31, vs. for controls: 0.22. The mean endothelial cell density of the eyes exposed to CL wear for more than 25 years (30 eyes) was 2575 cells/mm2 (mean CV: 0.36). Rather low densities (<2000 cells/mm2) were observed in 16 eyes of the CL group (8%). Cell densities less than 2500 cells/mm2 were observed in a total of 41 eyes (20%) in the CL group, whereas in the control group (100 eyes) all of the subjects, except one, had cell densities of more than 2500 cells/mm2 in both eyes. CONCLUSION: A subgroup of PMMA as well as soft contact lens wearers react not only with high pleomorphism and polymegethism but also with a decrease in endothelial cell density.

Adult↗

Autosomal dominant progressive external ophthalmoplegia with multiple deletions of mtDNA: clinical, biochemical, and molecular genetic features of the 10q-linked disease.

Autosomal dominant progressive external ophthalmoplegia (adPEO) is a mitochondrial disease characterized by accumulation of multiple large deletions of mtDNA in patients' tissues. We previously showed that the disease is genetically heterogeneous by assigning two nuclear loci predisposing to mtDNA deletions: one on chromosome 10q 23.3-24.3 in a Finnish family and one on 3p 14.1-21.2 in three Italian families. To reveal any locus-specific disease features, we report here the clinical, biochemical, and molecular genetic characteristics of the 10q-linked disease in the single family reported to date. All seven patients and four asymptomatic subjects had ragged-red fibers and multiple deletions of mtDNA in their muscle. Ptosis and external ophthalmoplegia were the major clinical findings, and depression or avoidant personality traits were frequently, but not consistently, present in the subjects carrying mutant mtDNA. In six of the subjects with mutant mtDNA, the activities of the respiratory chain complexes I or IV, or both, were below or within the low normal range. Two autopsy studies revealed the characteristic distribution of mutant mtDNA in these patients: highest proportion of mutant mtDNA is found in different parts of the brain, followed by the skeletal and ocular muscle, and the heart.

Adult↗

Interstitial radiotherapy of 25 parasellar/clival meningiomas and 19 meningiomas in the elderly. Analysis of short-term tolerance and responses.

I-125 seeds were permanently implanted into 25 parasellar-clival meningiomas (median age of patients, 56 y) and 19 globoid meningiomas in the elderly (median age of patients, 77 y) using stereotactic technique and 3-D dose planning. Total dose at the tumour margin was increased during the series from 100 Gy to 150 Gy. The procedure caused no mortality and no serious bleeding, but injury to the III cranial nerve due to puncture occurred in one (4%) of the 25 parasellar-clival meningiomas. In two (4.5%) of the 44 cases the postoperative CT scan showed a misplaced seed, located at the tumour surface. Nonenhancing hypodense rings developed around the seeds ('hot spots') with a median diameter of 10.5 mm at 12 months corresponding to a median initial activity of 8.7 mCi. In general, meningiomas responded by slow reduction in volume. The parasellar-clival meningiomas were followed-up for a median of 19 months (6-32), and so far 4 tumours have shrunk moderately, 13 slightly, and 5 not at all. Pre-operative III, V or VI cranial nerve signs were present in 17 patients and subsided in 8 of them. On the other hand, facial numbness developed or increased in 9 of the 25 patients, indicating that the V nerve is rather sensitive to this type of irradiation. In the 19 meningiomas of the elderly, the median follow-up time was 14 months (5-26). The median relative tumour volume was 46% at 12 months. Accounting for tumour-related deaths only, the actuarial survival rate was 78% at 12 months and 62% at 24 months. In general, brain oedema persisted despite reduction in tumour volume. Stereotactic implantation of I-125 seeds into intracranial meningiomas is relatively safe. Interstitial radiotherapy represents a potential tool in the control of medium-sized intracranial meningiomas with minimal brain oedema, but its long-term impact and untoward effects remain to be followed-up.

Adult↗

Comparison of etidocaine and bupivacaine + lidocaine in retrobulbar anaesthesia.

Etidocaine (15 mg/ml) was compared with bupivacaine (5 mg/ml) combined with lidocaine (10 mg/ml) in retrobulbar anaesthesia. One hundred and twelve patients were randomised into two groups. Supplemental anaesthesia was needed in 41% of cases of the etidocaine group and 32% of the bupivacaine-lidocaine group. Akinesia was evaluated by the surgeon both pre- and postoperatively and was found to be good or complete in more than 95% of both groups. Recovery from the motor and sensory block was investigated three times during the first 24 postoperative hours. The motor block of the orbicular muscle disappeared earlier than that of the globe. Akinesia lasted significantly longer in the etidocaine group than in the bupivacaine-lidocaine group: after 14 h 69% vs 100%, respectively, of the eyes showed normal movements. Sensation in the cornea was also regained more rapidly in patients treated with the mixture.

Anesthesia, Local↗

Presymptomatic DNA and MRI diagnosis of neurofibromatosis 2 with mild clinical course in an extended pedigree.

Neurofibromatosis 2 (NF2), a dominantly inherited disorder, typically manifests as bilateral vestibular schwannomas and predisposes to other nervous system tumors. In this study, we present a large pedigree with a benign course of NF2 (mild Gardner type) characterized by slowly growing vestibular schwannomas but few other manifestations. The family was thoroughly investigated with neurologic, ophthalmologic, and neuro-otologic methods including gadolinium-enhanced MRI of the head and spine and DNA linkage analysis. In the clinical analysis of 22 family members, MRI was superior to neuro-otologic methods in the detection of asymptomatic tumors. Based on the DNA linkage analyses we identified the NF2 mutation carriers with a high degree of certainty. These DNA markers (CRYB2, NEFH, D22S268, and D22S280) can also be used for presymptomatic diagnosis in other NF2 families. Early detection of NF2 gene mutation carriers has become possible using linkage analysis in familial NF2. MRI screening of carriers will reveal presymptomatic vestibular schwannomas (and other CNS tumors), making early intervention possible, but an efficient treatment strategy to prevent deafness has not yet been established.

Adult↗

Using magnetic coil signals with EOG signals in computer analysis of vestibulo-ocular reflex.

Since EOG signals are rather noisy, but magnetic coil signals almost noiseless, the latter type is a good reference to the former which is much easier to record. Concurrently recording magnetic coil and EOG signals we could verify some details as saccades which are often difficult to detect in noisy signals. It is important to recognise such phenomena in eye movement signals, because these affect the gain parameter computed between the vestibulo-ocular reflex signal and the head movement signal.

Algorithms↗

The value of visual evoked potentials in optic neuropathy of Graves' disease.

Visual evoked potentials (VEP) were tested in patients with ophthalmopathy (OP) of Graves' disease (GD) before treatment and half-a-year and 5-7 yr after orbital decompression (7 patients) or retrobulbar irradiation (3 patients). Five patients not requiring treatment for OP and 16 healthy subjects served as controls. Treatment of OP was given on clinical grounds including decreased visual acuity (VA) indicating optic neuropathy. Before treatment VA was decreased in 5 out of 19 eyes whereas VEP were abnormal in all. The mean latency at N60 both in the operated (83.1 +/- 21.6 ms) and in the irradiated groups (80.9 +/- 7.0 ms) was significantly different from that in the untreated group (62.6 +/- 8.2 ms; p < 0.001) and the healthy subjects (58.9 +/- 6.3; p < 0.001). At P120 only the latency of the operated group differed significantly from that of the other groups (p < 0.001). There was a relationship between the eye muscle changes seen on CT scans and the ophthalmopathy score (according to the classification of the American Thyroid Association) and the latency both at N60 and P120. A change from a V-shape to a W-shape of the waves occurred more often in the treated patients before therapy than in the other groups. Two patients had multiphase VEP in both eyes which improved after treatment. After adequate clinical response the visual acuity improved in one of the 5 patients with initially depressed VA. VEP, initially abnormal in all, improved in 7 of the 19 eyes (37%) but further deterioration was observed in 8 (42%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Visual evoked potentials after retrobulbar or periocular anaesthesia.

The effect of the local anaesthetic agent, etidocaine, on the optic nerve function was examined at regional ophthalmic anaesthesia. Visual evoked potential (VEP) was recorded before and 15 minutes after injection of the anaesthetic agent in 19 patients scheduled for elective cataract surgery (seven retrobulbar and 12 periocular). Both the anaesthetised--that is, the eye to be operated on--and the fellow eye were examined. In the retrobulbar group, two patients displayed non-recordable VEPs while one had virtually non-detectable waves following the anaesthesia. In two retrobulbarly anaesthetised eyes, later peaks were unidentifiable while two other eyes had decreased amplitudes. In the periocular group, in nine patients, there was no clearcut effect on VEP resulting from the anaesthetic. In three patients of this group mild changes in the anaesthetised eyes were found. The differences in the effect of retrobulbarly or periocularly injected anaesthetics on VEP are probably due to the different concentration of the anaesthetic agent around the optic nerve.

Aged↗

Visual evoked potentials in Basedow's ophthalmopathy before and after orbital decompression or retrobulbar irradiation.

VEP are an objective and a more sensitive sign of optical neuropathy in Graves' ophthalmopathy than is visual acuity. A correlation exists between VEP and the changes in the external eye muscles as visualized on CT scans. VEP should always be registered if CT changes are present. Improvement of optic neuropathy as evaluated from VEP seems to be remarkably infrequent.

Evoked Potentials, Visual↗

Corneal endothelium in pigmentary glaucoma and pigment dispersion syndrome.

Corneal endothelial cell density was determined in 64 eyes (32 patients) with pigmentary glaucoma and in 18 eyes (9 persons) with pigment dispersion syndrome without glaucoma. Twenty-eight healthy eyes served as controls. The glaucomas were stabilized with topical treatment or following laser trabeculoplasty or filtration surgery. The mean duration of the glaucoma was 7.6 years (SD 6.1 years) subsequent to diagnosis. Neither in the glaucomatous, nor in the pigment dispersion syndrome eyes, could any statistically significant difference in cell density be noted compared to the control series. Within the glaucoma group pressure level, topical treatment, laser trabeculoplasty and trabeculectomy did not have any statistically significant effect on cell counts. Distinct pleomorphism and polymegatism of the endothelial cells were observed in the study groups. The endothelial cell density decreased linearly with age.

Adult↗

Effect of sodium hyaluronate on immediate postoperative intraocular pressure after extracapsular cataract extraction and IOL implantation.

We studied 129 eyes which were undergoing extracapsular cataract extraction with IOL-implantation. The amount of residual Healon had a clearcut effect on the IOP elevations postoperatively. In eyes operated on with the intercapsular techniques, pressure elevations and the mean values during the first 6 postoperative hours were significantly higher than in eyes operated on with the planned ECCE (can opener-technique) (P less than 0.01). The pressure elevation reached the maximal values 8-12 h postoperatively and had normalized already at 24 h in most cases, except in glaucomatous eyes which at that time had significantly higher mean IOP values than the non-glaucomatous eyes (P less than 0.01). When operations were done with an air bubble no clearcut postoperative pressure increases could be observed. Our study indicates that a comparatively small amount of Healon may cause a pressure elevation and the amount left in the eye has a greater effect upon the level of the pressure than the duration of the pressure elevation. The less we inject Healon into the eye and the more we avoid leaving it there, the less risk we have of the possibility of vision deteriorating high postoperative intraocular pressure.

Aged↗